PostgreSQL 15 introduced the MERGE operator: https://www.postgresql.org/docs/15/sql-merge.html

This allows to INSERT/UPDATE/DELETE in one single statement. Currently we have this code:

https://gitlab.iscpif.fr/gargantext/haskell-gargantext/blob/dev/src/Gargantext/Core/NodeStory.hs#L506-513

i.e. we insert/update/delete rows by hand in Haskell (node stories).

The task is to rewrite this into PostgreSQL 15 MERGE.

This might help in tricky issues such as #303 (closed) (it's better to do one PostgreSQL transaction than split things in the backend).